(1.2)
In general, a vehicle is mounted with a vehicle display device arranged to display a measured value such as vehicle speed and engine revolution number, and in many vehicles said vehicle display device is constituted of an indicator instrument. The indicator instrument includes a meter case which houses a dial plate having a surface provided with indexes such as scale marks and numbers, letters or symbols, an indicator unit positioned in front of said dial plate to point to the indexes on the dial plate, a drive device which rotates the indicator shaft at which said indicator unit is attached in accordance with measured quantity, and a circuit board on which a circuit pattern and an electronic component and such are provided and on which said drive device is fixed.
To allow the indicator unit provided at such indicator instrument to be easily visible in the dark place as well, various technologies are disclosed in which the indicator member constituting the indicator unit is made of translucent synthetic resin which is translucent material, and in which light is guided from a light source into the indicator member to make the indicator member to be luminous. For example, a light-emitting indicator disclosed in Patent Literature 1 is provided with a hollow reflection part having a reflection face which reflects a part of light from a light source toward a distal end of the indicator.
For example, an indicator instrument 901 which is partially shown in FIG. 6 includes a dial plate 902, a light-emitting indicator 903 as an indicator unit, a drive device 904 having an indicator shaft 914 arranged to rotate in accordance with measured quantity, a circuit board 905 and a light source 906. The light-emitting indicator 903 includes an indicator main body 931 as an indicator member having a base part 940 and an indicator part 950 which are integrally molded from translucent synthetic resin, and a cover member 932 arranged to cover the indicator main body 931 and having a slit from which an upper face 953 of the indicator part 950 is exposed toward a viewer. This indicator main body 931 is arranged to guide the light received at the base part 940 to the indicator part 950 and direct the light to exit from the upper face 953 of the indicator part 950 toward the viewer, by which the upper face 953 of the indicator part 950 becomes luminous and visible through the slit of the cover member 932.
The base part 940 of the indicator main body 931 includes a circular cylindrical base part main body 941 to be attached to a distal end of the indicator shaft 914 which also functions as a light guide member, and a light receiving part 942 arranged to receive light L from the light source 906 which is guided by the indicator shaft 914. The indicator part 950 of the indicator main body 931 is provided with a pointing part 951 and a rearward part 952 extending from the base part 940 toward a pointing direction S1 intersecting a shaft center P of the indicator shaft 914 and toward a rear end direction S2 which is opposite of the pointing direction S1, respectively. A hollow reflection part 960 is provided inside of the indicator part 950 near an upper end 941a of the base part main body 941 so as to penetrate through the indicator part 950 in a widthwise direction (i.e. a direction perpendicular to a plane of paper in FIG. 6).
This hollow reflection part 960 is formed into a substantially triangular shape with a pointing direction reflection face 961, a rear end direction reflection face 962 and a transmission face 963. Furthermore, a corner 960a is formed at an intersection of the pointing direction reflection face 961 and the rear end direction reflection face 962 and is arranged at a location opposed to the light receiving part 942 of the base part 940. As shown in FIG. 7A, the indicator direction reflection face 961 reflects a part L1 of the light L received at the light receiving part 942 to the pointing direction S1 (i.e. the left direction in FIG. 7A) and allows other part L3 of the light L to transmit toward the transmission face 963. The rear end direction reflection face 962 reflects a part L2 of the light L received at the light receiving part 942 to the rear end direction S2 (i.e. the right direction in FIG. 7A) and allows other part L3 of the light L to transmit toward the transmission face 963.
The light L1 travels inside of the indicator part 951 toward the pointing direction S1 and exits from the upper face 953 adjacent to the pointing part 951, and the light L2 travels inside of the rearward part 952 toward the rear end direction S2 and exits from the upper face 953 adjacent to the rearward part 952, and the light L3 enters the transmission face 963 and then exits from the upper face 953 located above the hollow reflection part 960, by which the entire portion of the upper face 953 of the indicator part 950 becomes luminous. In FIG. 7A, the thickness of the arrow indicative of the light L3 represents the brightness of light, thus the thicker the arrow the higher the brightness, and the thinner the arrow the lower the brightness.
As shown in FIG. 7B, the light L3 entering the transmission face 963 has highest brightness at a section 963c of the transmission face 963 located right above the corner 960a, and the brightness becomes gradually lower as distant from the section 963c toward the a transmission face end 963a on the pointing direction S1 or toward a transmission face end 963b on the rear end direction S2. In the indicator part 950, the pointing part 951 is longer than the rearward part 952, thus needs more light reflected toward the pointing direction S1. Therefore, the pointing direction reflection face 961 is formed larger than the rear end direction reflection face 962, and the corner 960a is located to the rear end direction S2 with respect to the shaft center P of the indicator shaft 914.
Therefore, the section 963c with the highest brightness is also located to the rear end direction S2, thus the light entering near the transmission face end 963b located relatively near the section 963c can ensure the necessary brightness. However, the light entering near the transmission face end 963a located relatively distant from the section 963c is deficient in the brightness, causing a dark area D formed near an end on the pointing direction S1 side in a section R of the upper face 953 located above the hollow reflection part 960. Thus, as shown in FIG. 8, conventionally, the formation of the dark area D described above is prevented by inserting into the hollow reflection part 960 a light diffusing component 970 made of synthetic resin and such containing diffusing agent for transmitting and scattering the light and formed into a substantially same shape as the hollow reflection part 960, or by providing a filter member to the transmission face 963 as the light-emitting indicator disclosed in Patent Literature 1.
(2.2)
In general, a vehicle is mounted with a vehicle display device arranged to display measured value such as vehicle speed and engine revolution number, and in many vehicles said vehicle display device is constituted of an indicator instrument. The indicator instrument includes a meter case which houses a dial plate having a surface provided with indexes such as scale marks and numbers, letters or symbols, an indicator unit positioned in front of said dial plate to point to the indexes on the dial plate, a drive device which rotates the indicator shaft at which said indicator unit is attached in accordance with the measured quantity, and a circuit board on which a circuit pattern and an electronic component and such are provided and on which said drive device is fixed.
To allow the indicator unit provided at such indicator instrument to be easily visible in the dark place as well, various technologies are disclosed in which the indicator member constituting the indicator unit is made of translucent synthetic resin which is translucent material, and in which light is guided from a light source into the indicator member to make the indicator member to become luminous. For example, a light-emitting indicator disclosed in Patent Literature 1 is provided with a hollow reflection part having a reflection face which reflects a part of light from a light source toward a distal end of the indicator.
For example, an indicator instrument 901 which is partially shown in FIG. 17 includes a dial plate 902, a light-emitting indicator 903 as an indicator unit, a drive device 904 having an indicator shaft 914 arranged to rotate in accordance with measured quantity, a circuit board 905 and a light source 906. The light-emitting indicator 903 includes an indicator main body 931 as an indicator member having a base part 940 and an indicator part 950 which are integrally molded from translucent synthetic resin, and a cover member 932 arranged to cover the indicator main body 931 and having a slit from which an upper face 953 of the indicator part 950 is exposed toward a viewer. This indicator main body 931 is arranged to guide the light received at the base part 940 to the indicator part 950 and direct the light to exit from the upper face 953 of the indicator part 950 toward the viewer, by which the upper face 953 of the indicator part 950 becomes luminous and visible through the slit of the cover member 932.
The base part 940 of the indicator main body 931 includes a circular cylindrical base part main body 941 to be attached to a distal end of the indicator shaft 914 which also functions as a light guide member, and a light receiving part 942 arranged to receive light L from the light source 906 which is guided by the indicator shaft 914. The indicator part 950 of the indicator main body 931 is provided with a pointing part 951 and a rearward part 952 extending from the base part 940 toward a pointing direction S1 intersecting a shaft center P of the indicator shaft 914 and toward a rear end direction S2 which is opposite of the pointing direction S1, respectively. A hollow reflection part 960 is provided inside of the indicator part 950 near an upper end 941a of the base part main body 941 so as to penetrate through the indicator part 950 in a widthwise direction (i.e. a direction perpendicular to a plane of paper in FIG. 17).
This hollow reflection part 960 is formed into a substantially isosceles triangular shape with a pointing direction reflection face 961, a rear end direction reflection face 962 and a transmission face 963, each formed into a flat surface. Furthermore, a corner 960a is formed at an intersection of the pointing direction reflection face 961 and the rear end direction reflection face 962 and is arranged at a location opposed to the light receiving part 942 of the base part 940. As shown in FIG. 18, the indicator direction reflection face 961 reflects a part L1 of the light L received at the light receiving part 942 to the pointing direction S1 (i.e. the left direction in FIG. 18) and allows other part L3 of the light L to transmit toward the transmission face 963. The rear end direction reflection face 962 reflects a part L2 of the light L received at the light receiving part 942 to the rear end direction S2 (i.e. the right direction in FIG. 18) and allows other part L3 of the light L to transmit toward the transmission face 963.
The light L1 travels inside of the indicator part 951 toward the pointing direction S1 and exits from a section R1 of the upper face 953 located adjacent to the pointing part 951, and the light L2 travels inside of the rearward part 952 toward the rear end direction S2 and exits from a section R2 of the upper face 953 located adjacent to the rearward part 952, and the light L3 enters the transmission face 963 and then exits from a section R3 of the upper face 953 located above the hollow reflection part 960, by which the entire portion of the upper face 953 of the indicator part 950 becomes luminous.
(3.2)
In general, a vehicle is mounted with a vehicle display device arranged to display measured value such as vehicle speed and engine revolution number, and in many vehicles said vehicle display device is constituted of an indicator instrument. The indicator instrument includes a meter case which houses a dial plate having a surface provided with indexes such as scale marks and numbers, letters or symbols, an indicator unit positioned in front of said dial plate to point to the indexes on the dial plate, a drive device which rotates the indicator shaft at which said indicator unit is attached in accordance with measured quantity, and a circuit board on which a circuit pattern and an electronic component and such are provided and on which said drive device is fixed.
To allow the indicator unit provided at such indicator instrument to be easily visible in the dark place as well, various technologies are disclosed in which the indicator member constituting the indicator unit is made of translucent synthetic resin which is translucent material, and in which light is guided from a light source into the indicator member to make the indicator member to be luminous. For example, a light-emitting indicator disclosed in Patent Literature 1 is provided with a hollow reflection part having a reflection face which reflects a part of light from a light source toward a distal end of the indicator.
For example, an indicator instrument 901 which is partially shown in FIG. 28 includes a dial plate 902, a light-emitting indicator 903 as an indicator unit, a drive device 904 having an indicator shaft 914 arranged to rotate in accordance with measured quantity, a circuit board 905 and a light source 906. The light-emitting indicator 903 includes an indicator main body 931 as an indicator member having a base part 940 and an indicator part 950 which are integrally molded from translucent synthetic resin, and a cover member 932 arranged to cover the indicator main body 931 and having a slit from which an upper face 953 of the indicator part 950 is exposed toward a viewer. This indicator main body 931 is arranged to guide the light received at the base part 940 to the indicator part 950 and direct the light to exit from the upper face 953 of the indicator part 950 toward the viewer, by which the upper face 953 of the indicator part 950 becomes luminous and visible through the slit of the cover member 932.
The base part 940 of the indicator main body 931 includes a circular cylindrical base part main body 941 to be attached to a distal end of the indicator shaft 914 which also functions as a light guide member, and a light receiving part 942 arranged to receive light L from the light source 906 which is guided by the indicator shaft 914. The indicator part 950 of the indicator main body 931 is provided with a pointing part 951 and a rearward part 952 extending from the base part 940 toward a pointing direction S1 intersecting a shaft center P of the indicator shaft 914 and toward a rear end direction S2 which is opposite of the pointing direction S1, respectively. A hollow reflection part 960 is provided inside of the indicator part 950 near an upper end 941a of the base part main body 941 so as to penetrate through the indicator part 950 in a widthwise direction (i.e. a direction perpendicular to a plane of paper in FIG. 28).
This hollow reflection part 960 is formed into a substantially isosceles triangular shape with a pointing direction reflection face 961, a rear end direction reflection face 962 and a transmission face 963. Furthermore, a corner 960a is formed at an intersection of the pointing direction reflection face 961 and the rear end direction reflection face 962 and is arranged at a location opposed to the light receiving part 942 of the base part 940. As shown in FIG. 29, the indicator direction reflection face 961 reflects a part L1 of the light L received at the light receiving part 942 to the pointing direction S1 (i.e. the left direction in FIG. 29) and allows other part L3 of the light L to transmit toward the transmission face 963. The rear end direction reflection face 962 reflects a part L2 of the light L received at the light receiving part 942 to the rear end direction S2 (i.e. the right direction in FIG. 29) and allows other part L3 of the light L to transmit toward the transmission face 963.
The light L1 travels inside of the indicator part 951 toward the pointing direction S1 and exits from an upper face 953a of the pointing part 951, and the light L2 travels inside of the rearward part 952 toward the rear end direction S2 and exits from an upper face 953b of the rearward part 952.
However, the light L1 reflected by the pointing direction reflection face 961 travels at an angle with respect to the pointing direction reflection face 961, thus less light travels along the pointing direction reflection face 961. Thus, there is a problem that amount of light exiting from the section R of the upper face 953a of the pointing part 951 near the hollow reflection part 960 becomes less, causing a dark area formed at this section R and thus causing non-uniformity in the brightness at the upper face 953.
A indicator member 811 disclosed in Patent Literature 2 shown in FIG. 30 includes a base part 811a and an indicator part 811b having a pointing part 811b1 extending to one direction from the base part 811a and a balance part 811b2 as a rearward part extending to the other direction which is opposite of said one direction. A hollow reflection part 811c is provided at a connection section of the pointing part 811b1 and the balance part 811b2, the hollow reflection part 811c being arranged to reflect the light from the base part 811a toward a distal end direction of the pointing part 811b1 and toward a rear end direction of the balance part 811b2.
A rearward diffuse reflection face 811b3 is provided at a proximal portion of the base part 811a and the balance part 811b2. This rearward diffuse reflection face 811b3 is arranged to face to and substantially parallel to a rearward reflection face 811c2 of the hollow reflection part 811c such that the light reflected on the rearward reflection face 811c2 is reflected toward an upper face of the balance part 811b2. Thus, the above-mentioned problem can be solved by adjusting the rearward diffuse reflection face 811b3 to reflect the light toward a section of the upper face of the balance part 811b2 near the hollow reflection part 811c. 
(4.2)
In general, a vehicle is mounted with a vehicle display device arranged to display measured value such as vehicle speed and engine revolution number, and in many vehicles said vehicle display device is constituted of an indicator instrument. The indicator instrument includes a meter case which houses a dial plate having a surface provided with indexes such as scale marks and numbers, letters or symbols, an indicator unit positioned in front of said dial plate to point to the indexes on the dial plate, a drive device which rotates the indicator shaft at which said indicator unit is attached in accordance with measured quantity, and a circuit board on which a circuit pattern and an electronic component and such are provided and on which said drive device is fixed.
To allow the indicator unit provided at such indicator instrument to be easily visible in the dark place as well, various technologies are disclosed in which the indicator member constituting the indicator unit is made of translucent synthetic resin which is translucent material, and in which light is guided from a light source into the indicator member to make the indicator member to be luminous. For example, a light-emitting indicator disclosed in Patent Literature 1 is provided with a hollow reflection part having a reflection face which reflects a part of light from a light source toward a distal end of the indicator. Furthermore, an instrument disclosed in Patent Literature 3 includes a translucent indicator shaft, and an indicator receives the light from the light source guided in the indicator shaft, and the indicator emits light by the received light.
For example, an indicator instrument 901 which is partially shown in FIG. 41 includes a dial plate 902, a light-emitting indicator 903 as an indicator unit, a drive device 904 having an indicator shaft 914 arranged to rotate in accordance with measured value, a circuit board 905 and a light source 906. The light-emitting indicator 903 includes an indicator main body 931 as an indicator member having a base part 940 and an indicator part 950 which are integrally molded from translucent synthetic resin, and a cover member 932 arranged to cover the indicator main body 931 and having a slit from which an upper face 953 of the indicator part 950 is exposed toward a viewer. This indicator main body 931 guides the light received at the base part 940 to the indicator part 950 and directs the light to exit from the upper face 953 of the indicator part 950 toward the viewer, thereby being luminous and visible through the slit of the cover member 932.
The base part 940 of the indicator main body 931 includes a shaft receiving part 941 arranged to guide the light from the light source 906 and arranged to be attached to a distal end of the indicator shaft 914, and a light receiving part 942 arranged to receive light L guided from the light source 906 by the indicator shaft 914 and exited from the distal end of the indicator shaft 914. The indicator part 950 of the indicator main body 931 is provided with a pointing part 951 and a rearward part 952 extending from the base part 940 toward a pointing direction S1 intersecting a shaft center P of the indicator shaft 914 and toward a rear end direction S2 which is opposite of the pointing direction S1, respectively. A hollow reflection part 960 is provided inside of the indicator part 950 near the light receiving part 942 of the base part main body 941 so as to penetrate through the indicator part 950 in a widthwise direction (i.e. a direction perpendicular to a plane of paper in FIG. 41).
This hollow reflection part 960 is formed into a substantially triangular shape with a pointing direction reflection face 961, a rear end direction reflection face 962 and a transmission face 963. Furthermore, a corner 960a is formed at an intersection of the pointing direction reflection face 961 and the rear end direction reflection face 962 and is arranged at a location opposed to the base part 940. As shown in FIG. 42, the indicator direction reflection face 961 reflects a part L1 of the light L received at the light receiving part 942 to the pointing direction S1 (i.e. the left direction in FIG. 42) and allows other part L3 of the light L to transmit toward the transmission face 963. The rear end direction reflection face 962 reflects a part L2 of the light L received at the light receiving part 942 to the rear end direction S2 (i.e. the right direction in FIG. 42) and allows other part L3 of the light L to transmit toward the transmission face 963. The light L1 is reflected in the pointing part 951 and travels toward the pointing direction S1 and exits from the upper face 953 located adjacent to the pointing part 951, and the light L2 is reflected in the rearward part 952 and travels toward the rear end direction S2 and exits from the upper face 953 located adjacent to the rearward part 952, and the light L3 enters the transmission face 963 and then exits from the upper face 953 located above the hollow reflection part 960, by which the entire portion of the upper face 953 of the indicator part 950 becomes luminous.